This is a proposal to obtain a modern multi-optional spectro polarimeter for the Chemisty Department of the University of New Mexico. This instrument will have the capabilities to perform 1) magnetic circular dichroism, 2) fluorescence-detected circular dichroism (FDCD), 3) fast scanning and averaging of large number of spectra, 4) large data storage accessories and specialized software for data processing, 5) low-temperature capabilities, and 6) stopped flow accessory for kinetic studies. The three main users of this instrument will be Dr. Carlos Bustamante (Chemistry Department), Dr. Mark R. Ondrias (Chemistry Department), and Dr. David G. Bear (Cell Biology Department). Dr. Bustamante proposes to study and characterize the condensation of DNA in vitro by following the appearance of the so-called Psi-type CD anomalies, observed in compacted forms of DNA. Recently, a theory of these effects has been developed in Dr. Bustamante's laboratory. Dr. Mark R. Ondrias is currently studying the transient and steady state Raman spectra of multi-heme proteins. Dr. Ondrias proposes to characterize the state of oxidation of trapped photolytic transients via magnetic circular dichroism spectroscopy. Dr. David G. Bear proposes to study the binding of the transcription termination factor rho to specific messenger RNA by following the changes induced in the circular dichroism upon binding. Each co-P.I. will have access to 25% of the total available user time of the instrument. In addition, this proposal contains the contribution of Professor Fritz S. Allen as a user outside of the main user group. Dr. Allen plans to study the molecular mechanisms of allosteric regulation of liver phosphofructo-kinase, by conducting stopped-flow studies and following the CD changes that accompany NAD/NADH conversion.